Audio forensics is the close examination of audio files for legal purposes. Audio forensic experts examine the recording in a forensics lab to determine its authenticity. The examination typically involves checking integrity, improving speech clarity, transcribing dialogue, comparing voices, and reconstructing event timelines.
HOW AUDIO EVIDENCE IS COLLECTED
Audio evidence collection must be performed per industry best practices. The Scientific Working Group on Digital Evidence (SWGDE) outlines acceptable methods for acquiring audio files for forensic analysis:
FORENSIC AUDIO AUTHENTICATION AND ANALYSIS
After the evidence has been collected, the audio forensics expert will inspect the recording to determine its authenticity. In this digital age of advanced software editing, it is easy for an audio file to be tampered with, making it inauthentic. The expert will examine the recording using SWGDE best practices to determine if an audio file has integrity.
Audio files can also be enhanced to remove unwanted background noise so dialogue can be heard more clearly. Various filters are applied to the recording to achieve this, such as:
HOW FORENSIC AUDIOLOGY IS USED IN COURT
Audio files that have been examined and clarified by an audio forensic expert can be used in court as evidence. The audio forensic scientist may serve as an expert witness and provide reports and testimony on the results of their investigation. The information they provide includes everything from their methodology to unbiased opinions on the results obtained.